Turbo Molecular Pump Stator Disc Layout for Thermal Isolation
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Solution Overview
Problem
Existing vacuum pumps, particularly those with a Siegbahn exhausting mechanism, face challenges in preventing the transfer of heat between stator discs, which can lead to temperature imbalances and potential performance degradation.
Innovation Solution
The vacuum pump design includes stator discs with annular protruding portions and recessed portions for precise positioning, along with a Siegbahn exhausting mechanism featuring spiral grooves, to minimize heat transfer between adjacent stator discs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If stator discs are arranged adjacently in axial direction for Siegbahn exhausting mechanism, then gas exhaust function is improved, but heat transfer between stator discs occurs causing temperature imbalance
Solution Approach 1:
The stator disc is segmented into multiple functional regions: an annular first outer peripheral side protruding portion for axial positioning, an annular first inner peripheral side protruding portion for radial and circumferential positioning, and a spatial portion (first recessed portion) between them. This segmentation allows the positioning functions to be distributed across different structural elements, enabling precise positioning while maintaining thermal isolation between adjacent stator discs.
Solution Approach 2:
The spatial portion (first recessed portion) acts as a thermal barrier or intermediary layer between adjacent stator discs. By providing a recessed spatial region at the contact interface, heat transfer path is interrupted or reduced, preventing direct thermal conduction between the high-temperature downstream side and low-temperature upstream side while still allowing mechanical positioning to occur.
2Manufacturing precision
If multiple positioning features are added to stator discs, then positioning precision is improved, but device complexity increases
Solution Approach 1:
The stator disc design integrates multiple positioning functions into a single component structure. The annular first outer peripheral side protruding portion provides axial positioning, while the annular first inner peripheral side protruding portion provides both radial and circumferential positioning. This multi-functional design achieves precise positioning in all necessary directions without requiring separate positioning components, thereby reducing overall device complexity while maintaining high positioning precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively suppresses heat transfer between stator discs, maintaining temperature stability and enhancing the pump's performance and reliability.
Implementation Method 1
one of the contact surfaces of a pair of spacers sandwiching one of the plurality of stages of stator blades is formed to be a concavo-convex surface... conduction heat from the pump casing to the spacers can be reduced
Implementation Method 2
The Siegbahn exhausting mechanism is a mechanism to exhaust gas by interaction with a plurality of stator discs formed with spiral grooves and a plurality of rotor discs. In the Siegbahn exhausting mechanism, the downstream side of a gas flow is heated by a heater
Implementation Method 3
the upstream side thereof is cooled by a cooling medium
Data Source
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AI summary
[Problem] To provide a vacuum pump and a stator disc that can suppress transfer of heat between a plurality of stator discs. [Solving Means] Provided is a turbo molecular pump (vacuum pump) 100 that includes an outer cylinder (casing) 127, a rotor shaft (rotating shaft) 113 that is rotatably supported inside the outer cylinder 127, a plurality of rotor discs 200 that rotate together with the rotor shaft 113, and a plurality of stator discs 201 that are alternately arranged between the plurality of rotor discs 200, the turbo molecular pump exhausting gas by interaction between the plurality of rotor discs 200 and the plurality of stator discs 201, wherein the plurality of stator discs 201 include a first stator disc 201a and a second stator disc 201b that is adjacent to the first stator disc 201a in an axial direction, the first stator disc 201a has an outer peripheral side protruding portion (first contact portion) 210 that contacts the second stator disc 201b to perform positioning in the axial direction, and the outer peripheral side protruding portion 210 has a spatial portion 216 that is provided between the outer peripheral side protruding portion 210 and the second stator disc 201b.